Pharmacologic Category

Use: Labeled Indications

Temporary relief of coughs and upper respiratory symptoms associated with allergy or the common cold

Contraindications

Hypersensitivity to promethazine, dextromethorphan, or any component of the formulation (cross-reactivity between phenothiazines may occur); treatment of lower respiratory tract symptoms, including asthma; use with or within 14 days of MAO inhibitor therapy

Dosing: Renal Impairment

There are no dosage adjustments provided in the manufacturer’s labeling.

Dosing: Hepatic Impairment

Adults: There are no dosage adjustments provided in the manufacturer’s labeling; use with caution (cholestatic jaundice has been reported with use).

Children ≥2 years and Adolescents: The manufacturer recommends to avoid use in pediatric patients with signs and symptoms of hepatic disease (extrapyramidal symptoms caused by promethazine may be confused with CNS signs of hepatic disease).

Dietary Considerations

Increase dietary intake of riboflavin.

Drug Interactions

Abiraterone Acetate: May increase the serum concentration of CYP2D6 Substrates (High risk with Inhibitors). Management: Avoid concurrent use of abiraterone with CYP2D6 substrates that have a narrow therapeutic index whenever possible. When concurrent use is not avoidable, monitor patients closely for signs/symptoms of toxicity. Consider therapy modification

Buprenorphine: CNS Depressants may enhance the CNS depressant effect of Buprenorphine. Management: Consider reduced doses of other CNS depressants, and avoiding such drugs in patients at high risk of buprenorphine overuse/self-injection. Initiate buprenorphine patches (Butrans brand) at 5 mcg/hr in adults when used with other CNS depressants. Consider therapy modification

Chlormethiazole: May enhance the CNS depressant effect of CNS Depressants. Management: Monitor closely for evidence of excessive CNS depression. The chlormethiazole labeling states that an appropriately reduced dose should be used if such a combination must be used. Consider therapy modification

Doxylamine: May enhance the CNS depressant effect of CNS Depressants. Management: The manufacturer of Diclegis (doxylamine/pyridoxine), intended for use in pregnancy, specifically states that use with other CNS depressants is not recommended. Monitor therapy

Epinephrine (Racemic): Promethazine may diminish the vasoconstricting effect of Epinephrine (Racemic). Management: Monitor for diminished vasoconstrictive effects of racemic epinephrine (e.g., diminished efficacy when used for gingival retraction). This interaction is likely of less concern in patients receiving epinephrine for other purposes (e.g., bronchodilation). Monitor therapy

HYDROcodone: CNS Depressants may enhance the CNS depressant effect of HYDROcodone. Management: Avoid concomitant use of hydrocodone and benzodiazepines or other CNS depressants when possible. These agents should only be combined if alternative treatment options are inadequate. If combined, limit the dosages and duration of each drug. Consider therapy modification

Opioid Analgesics: CNS Depressants may enhance the CNS depressant effect of Opioid Analgesics. Management: Avoid concomitant use of opioid analgesics and benzodiazepines or other CNS depressants when possible. These agents should only be combined if alternative treatment options are inadequate. If combined, limit the dosages and duration of each drug. Consider therapy modification

OxyCODONE: CNS Depressants may enhance the CNS depressant effect of OxyCODONE. Management: Avoid concomitant use of oxycodone and benzodiazepines or other CNS depressants when possible. These agents should only be combined if alternative treatment options are inadequate. If combined, limit the dosages and duration of each drug. Consider therapy modification

Perampanel: May enhance the CNS depressant effect of CNS Depressants. Management: Patients taking perampanel with any other drug that has CNS depressant activities should avoid complex and high-risk activities, particularly those such as driving that require alertness and coordination, until they have experience using the combination. Consider therapy modification

Pramlintide: May enhance the anticholinergic effect of Anticholinergic Agents. These effects are specific to the GI tract. Consider therapy modification

QuiNIDine: May increase the serum concentration of Dextromethorphan. Management: Avoid concurrent use of these agents when possible, unless the increased psychoactive effects of dextromethorphan are desired. Since codeine activation is also inhibited by quinidine, codeine is unlikely to be suitable as an alternative antitussive. Consider therapy modification

Selective Serotonin Reuptake Inhibitors: May enhance the serotonergic effect of Dextromethorphan. Selective Serotonin Reuptake Inhibitors may increase the serum concentration of Dextromethorphan. Management: Avoid the concurrent use of dextromethorphan and SSRIs, particularly fluoxetine and paroxetine, when possible. The risk for this interaction may persist for several weeks following discontinuation of fluoxetine or paroxetine. Exceptions: FluvoxaMINE. Consider therapy modification

Serotonin Modulators: May enhance the adverse/toxic effect of other Serotonin Modulators. The development of serotonin syndrome may occur. Exceptions: Nicergoline; Tedizolid. Monitor therapy

Sodium Oxybate: May enhance the CNS depressant effect of CNS Depressants. Management: Consider alternatives to combined use. When combined use is needed, consider minimizing doses of one or more drugs. Use of sodium oxybate with alcohol or sedative hypnotics is contraindicated. Consider therapy modification

Suvorexant: CNS Depressants may enhance the CNS depressant effect of Suvorexant. Management: Dose reduction of suvorexant and/or any other CNS depressant may be necessary. Use of suvorexant with alcohol is not recommended, and the use of suvorexant with any other drug to treat insomnia is not recommended. Consider therapy modification

Tapentadol: May enhance the CNS depressant effect of CNS Depressants. Management: Avoid concomitant use of tapentadol and benzodiazepines or other CNS depressants when possible. These agents should only be combined if alternative treatment options are inadequate. If combined, limit the dosages and duration of each drug. Consider therapy modification

Zolpidem: CNS Depressants may enhance the CNS depressant effect of Zolpidem. Management: Reduce the Intermezzo brand sublingual zolpidem adult dose to 1.75 mg for men who are also receiving other CNS depressants. No such dose change is recommended for women. Avoid use with other CNS depressants at bedtime; avoid use with alcohol. Consider therapy modification

Test Interactions

See individual agents.

ALERT: U.S. Boxed Warning

Pediatrics:

Do not use in patients younger than 2 years of age because of potential for fatal respiratory depression. Administer with caution to children older than 2 years of age.

• Orthostatic hypotension: May cause orthostatic hypotension; use with caution in patients at risk of this effect or in those who would not tolerate transient hypotensive episodes (cerebrovascular disease, cardiovascular disease, hypovolemia, or concurrent medication use which may predispose to hypotension/bradycardia).

• Sedation: May be sedating, use with caution in disorders where CNS depression is a feature; patients must be cautioned about performing tasks which require mental alertness (eg, operating machinery or driving).

• Bone marrow suppression: Use with caution in patients with bone marrow suppression; leukopenia and agranulocytosis have been reported.

• Cardiovascular disease: Use with caution in patients with severe cardiovascular disease.

• Glaucoma: Use with caution in patients with narrow-angle glaucoma; condition may be exacerbated by cholinergic blockade. Screening is recommended.

• Hepatic impairment: Use with caution in patients with hepatic impairment; cholestatic jaundice has been reported with promethazine use. Avoid use in pediatric patients with signs and symptoms of hepatic disease (extrapyramidal symptoms caused by promethazine may be confused with CNS signs of hepatic disease).

• Myasthenia gravis: Use with caution in patients with myasthenia gravis; condition may be exacerbated by cholinergic blockade.

• Parkinson disease: Use with caution in patients with Parkinson disease; may have increased risk of tardive dyskinesia.

• Respiratory disease: Use with caution in patients with severe respiratory disease (asthma, COPD, sleep apnea); may lead to potentially fatal respiratory depression.

• Seizures: Use with caution in patients at risk of seizures, including those with a history of seizures, head trauma, brain damage, alcoholism, or concurrent therapy with medications which may lower seizure threshold.

• Sedatives: Effects may be potentiated when used with other sedative drugs or ethanol.

Special populations:

• CYP2D6 poor metabolizers: Dextromethorphan is metabolized by hepatic CYP2D6. Poor metabolizers of CYP2D6 may have exaggerated or prolonged effects of dextromethorphan. Increased risk may be seen with concomitant use of potent CYP2D6 inhibitors; use with caution (Abduljalil 2010; Jurica 2012; Sager 2014; Zhou 2009).

• Pediatric: [U.S. Boxed Warning]: Safety and efficacy of this combination have not been established in children <2 years of age (use of promethazine is contraindicated). In children ≥2 years, use the lowest possible dose; other drugs with respiratory depressant effects should be avoided. Avoid use in children who may have Reye syndrome or hepatic disease as adverse reactions caused by promethazine may be confused with signs of primary disease.

Pregnancy Risk Factor

C

Pregnancy Considerations

Reproduction studies have not been conducted with this combination. Refer to individual monographs.

Patient Education

• Discuss specific use of drug and side effects with patient as it relates to treatment. (HCAHPS: During this hospital stay, were you given any medicine that you had not taken before? Before giving you any new medicine, how often did hospital staff tell you what the medicine was for? How often did hospital staff describe possible side effects in a way you could understand?)

• Educate patient about signs of a significant reaction (eg, wheezing; chest tightness; fever; itching; bad cough; blue skin color; seizures; or swelling of face, lips, tongue, or throat). Note: This is not a comprehensive list of all side effects. Patient should consult prescriber for additional questions.

Intended Use and Disclaimer: Should not be printed and given to patients. This information is intended to serve as a concise initial reference for healthcare professionals to use when discussing medications with a patient. You must ultimately rely on your own discretion, experience and judgment in diagnosing, treating and advising patients.